MEAS_1/2 have always largest value,
whereas MEAS_3/4 have always smallest value of all measurements data.
Depending on temperature (pressure?) the MEAS_EX3 and MEAS_EX4 have the same characteristic
(both values change in the same direction with similar slope).
Channel MEAS_EX1 and MEAS_EX2 have also similar value, but its characteristics have
different sign for slope (when one increases, the other decreases).

GPS subframe payload (0x67)

expected payload length: 122

offset (B)

lenght (B)

content

description

0

4

GPS_TIME (int32)

GPS time - seconds from week start, repesented as ms

4

2

GPS_BLOB_0

???

6

8

GPS_PRN

PRN for each tracked satelite

14

12

GPS_STAT_1

signal strength, fix status …

26

88

GPS_DATA_1

doppler, pseudorange, …

GPS_PRN

List of pseudorange sequence number for each recieving satelite, 0 == no satelite.